Problems of motion coordination of multiple entities are addressed in this paper. These problems are dealt on the abstract level where they can be viewed as tasks of constructing a spatial-temporal plan for a set of identical mobile entities.
The entities reside in a certain environment where they can move. Each entity need to reach a given goal position supposed it is starting from some initial position.
The most abstract formal representations of coordinated motion problems are known as “pebble motion on a graph” and “multi-robot path planning”. The existent algorithms for pebble motion and multi-robot problems were suspected of generating solutions containing redundancies.
This hypothesis eventually confirmed in this work. We present several techniques for identifying and eliminating redundancies from solutions generated by existent algorithms.
An extensive experimental evaluation was performed and it showed that the quality of generated solutions can be improved up to the order of magnitude. We also identify parameters characterizing instances of problems where a significant improvement is expectable.